From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 013.lax.mailroute.net (013.lax.mailroute.net [199.89.1.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A57DC3446C7; Sun, 18 Oct 2026 16:41:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792341690; cv=none; b=RMz6wdTGlfYy0QEuGmGqnDi9ODPg/j/c5U5tKSwNh02zJekVXFtYruA7X+MqQC2ateuxsatecihN4Le4SM7dqCe32jRpW2g4TmsG9F92fWQk5sEiEK9Ryz+jCpOZer3T7bn2UOOatAefpaF+LYfL+VlsJXX3C5u0IvaJZsFLwns= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792341690; c=relaxed/simple; bh=o8hJVdeaVwXZ8od6XDgi46XGIhr3WOQHprnfFbLcHX8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=IHYI7nsg7Q8DEZ81E/g+KkE9E8YwEiET806Tvnza6DuPUJvhYFZwEEBICe/abfXs+nqU1qfZhOODxuaSsDjikEqBygapX1ba2Pyrbyy9yoh0j9OIZIr91KNazMpNcsuwHMDa0peWcXoR1R5FXLAKpHhdHG8UL/QuF5k4hTeJaqs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=U0O8yl6P; arc=none smtp.client-ip=199.89.1.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="U0O8yl6P" Received: from localhost (localhost [127.0.0.1]) by 013.lax.mailroute.net (Postfix) with ESMTP id 4j74FF1l9Bzlfvpn; Sun, 18 Oct 2026 16:41:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:content-type:content-type:in-reply-to :from:from:content-language:references:subject:subject :user-agent:mime-version:date:date:message-id:received:received; s=mr01; t=1792341678; x=1794933679; bh=4AWHPp8lSPd/t1bYHj068BCx rU2/TvcFgspDWB8/VwU=; b=U0O8yl6PoHeQLQeXxak6P+O3k6tqggbdiAvFtBns GQfnd02Ktyhao0j8McZHkR3rYJVG5ICbL0829MBk9YOAfSp/B/LobVjNmKTt+N3a jaE1bUKTM4mD5Yk/xoO/msw2zV9CVFY9/yd1oZKzVLQF70q/buqYylW1NScJrz0y Aoac69LGdAc/WIuqRQZVoVYrb4SDucLfYtAfN8TRgESj4wTwpgfRtkkSwFI2hOz+ za0fx6pFYdXlaTOMns49yc8rYGjpEfeU9yuNdqVlE0or2MitRws0I1FRLAr8QKCT 8pYsU+vJwMEdUMY9bcrHrDyFRB8HDeP0NP6uDP/Bk+0Mlw== X-Virus-Scanned: by MailRoute Received: from 013.lax.mailroute.net ([127.0.0.1]) by localhost (013.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id DynZCCGGcDLd; Sun, 18 Oct 2026 16:41:18 +0000 (UTC) Received: from [192.168.51.14] (c-24-6-239-25.hsd1.ca.comcast.net [24.6.239.25]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 013.lax.mailroute.net (Postfix) with ESMTPSA id 4j74F91fbHzlfvpd; Sun, 18 Oct 2026 16:41:16 +0000 (UTC) Message-ID: Date: Sun, 18 Oct 2026 09:41:14 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/6] scsi: make SG_IO user copyback failure-safe To: Wang Yingjie , "James.Bottomley@HansenPartnership.com" , "mkp@kernel.org" Cc: "yangxiuwei@kylinos.cn" , "axboe@kernel.dk" , "linux-scsi@vger.kernel.org" , "io-uring@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: Content-Language: en-US From: Bart Van Assche In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/18/26 8:41 AM, Wang Yingjie wrote: > Several SCSI passthrough completion paths touch userspace while their > completed request still owns a queue tag. Sense or READ-bounce copyback > can fault on a mapping backed by the same one-tag device, leaving the > nested I/O unable to obtain the retained tag. The synchronous and > io_uring BSG paths additionally discard data-copyback failures. How common are one-tag devices? Has it been considered to disable SG_IO for one-tag devices instead of complicating the SG_IO implementation? Thanks, Bart.